All the pitfalls of concurrency are there - in particular when executing non-idempotent functions multiple times before previous executions finish, then you need mutexes!
This is one of those "in practice, theory and practice are different" situations.
There is nothing in the async world that looks like a parallel race condition. Code runs to completion until it deterministically yields, 100% of the time, even if the location of those yields may be difficult to puzzle out.
And so anyone who's ever had to debug and reason about a parallel race condition is basically laughing at that statement. It's just not the same.
In particular promise.all([f,f,f]) where I want to ensure that I only Run the body of f a single time.